Two sets of correlations are reported—observed score correlations and true score correlations.
Observed score correlations are the correlations between the scores obtained on the different tests
by individual test takers. True score correlations, or disattenuated correlations, are estimates of the
correlations between scores that would have been obtained if the tests were perfectly reliable. True
score correlations are estimated statistically from the observed score correlations using estimates of
test reliabilit